There are many ways to embellish drawn thread and so give it a looking like lace. The purpose is to join threads together.
Coral knot is the basic stitch to drawn thread embroidery, I think. Step by step photos:

after having done the hem stitch in both sides, the thread goes under the satin stitch at the drawn thread edge and comes up in the middle;
then the needle goes under the thread (which is forming a loop) and two hem stitch bunches and comes over the thread creating a knot – it’s much easier to do than to write about this, believe me!

e puxa-se o fio! Repetir uma e outra vez até dominar bem a tensão do fio. then you pull the thread! You have to repeat again and again to get the right thread tension.

Só com este ponto fazem-se muitos motivos: juntar três grupos de fiosJust with this stitch you can do many designs: joining three hem stitch bunches